<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>CSS样式表</title>
    <style>
    	h1,h2,h3,h4,h5,h6{
    		color:blue;
    		font-size:20px;
    	}
      </style>
</head>
<body>
      <h1>123456789123456798</h1>
      <h2>123456789123456798</h2>
      <h3>123456789123456798</h3>
      <h4>123456789123456798</h4>
      <h5>123456789123456798</h5>
      <h6>123456789123456798</h6>
</body>
</html>